Evaluating the Role of Retrieval Bags in Mitigating Contamination During Minimally Invasive Colorectal Surgery

<b>Objective:</b> To evaluate the extent of intraoperative bacterial and tumour cell spillage during minimally invasive colorectal surgery and to assess the protective value of systematic specimen retrieval using a tear-proof extraction bag. <b>Methods:</b> This multicentre, prospective observational study included patients undergoing conventional or single-port laparoscopic colorectal surgery for adenocarcinoma, premalignant polyps, or chronic diverticulitis. Three intraoperative samples were obtained for microbiological and cytological analysis: after pneumoperitoneum induction (sample 1), after vascular ligation and bowel division (sample 2), and after specimen extraction using a retrieval bag (sample 3). <b>Results:</b> Eighty-eight patients were included. Bacterial contamination increased significantly throughout the procedure occurring in 11.4% of sample 1, 37.5% of sample 2, and 67% of sample 3 (<i>p</i> < 0.001). When sample 1 was positive, sample 2 was positive in 100% of cases; when sample 2 was positive, sample 3 was positive in 79% of cases. In 33 patients (37.5%), bacterial growth was detected exclusively in sample 3. Contamination in sample 2 was significantly associated with surgical approach (<i>p</i> = 0.013), anastomotic technique (<i>p</i> = 0.022), and malignant disease (<i>p</i> = 0.038). A longer hospital stay was significantly associated with contamination in samples 1 and 2 (<i>p</i> = 0.014 and <i>p</i> < 0.001, respectively). No tumour cells were detected in any sample, except for one case showing atypical cells without clinical relevance in sample 3. <b>Conclusions:</b> Intraoperative bacterial contamination progressively increases during minimally invasive colorectal surgery, peaking after specimen extraction. Most clinical and surgical variables did not significantly influence contamination rates. The use of a specimen retrieval bag demonstrated a potential protective effect by containing bacterial spillage. However, no protective effect regarding tumour cell dissemination could be demonstrated based on cytology analysis.